Hi Englishman,
Have you ever tried the prescription drug oxybutynin? It is also known as Ditropan or here in Ireland it's named Cystrin (maybe this is the same in England).
I take it for my hyperhidrosis and I also get facial blushing, especially when I meet new people or am put in an awkward situation. The Cystrin tablets that I take completely ease my sweating to normal levels and completely stops any facial blushing. The only side effect of this drug that I have had is a slight dry mouth. But overall it is worth it.
I would strongly recommend consulting a doctor and mentioning oxybutynin/Ditropan/Cystrin, if you have not already.
Don't give up dude. This is a good forum, you have plenty of people to confide with.
Sean